1. Field of the Invention
The present invention relates to a playback apparatus, and in particular to an apparatus that generates a representative image of a moving image recorded in a recording medium.
2. Description of the Related Art
In recent years, recording playback apparatuses such as video cameras have appeared that capture moving images, record the captured images in a random access recording medium such as a flash memory card, and play back the images therefrom. Apparatuses of this type ordinarily have a configuration in which when recorded moving images are to be played back, representative images of respective scenes of the moving images recorded in the recording medium are generated and displayed, and a user selects a desired scene from among the representative images.
If a representative image is to be generated, moving image data recorded in the recording medium is played back and decoded, and one frame of the data is selected as a representative image, for example. Then, the size of the image data of the selected frame is reduced to a predetermined size suitable for display. The representative images of scenes obtained in this way are displayed in a list on the same screen as an index screen. Further, if the user instructs the switching of the index screen, processing for generating the above-described representative images is executed again, and the display screen is updated.
Thus, if a screen showing the list of representative images is to be displayed, it is necessary to sequentially play back and decode image data of scenes from the recording medium. Accordingly, there is a problem in that it takes time to display a screen showing the list of representative images (thumbnails).
In view of this, a configuration has been proposed in which representative image data that has been once displayed is stored in a memory in the apparatus, and if the same representative image is to be displayed again, the list screen is displayed without playing back moving image data from the recording medium (see Japanese Patent Laid-Open No. 2005-253087, for example).
However, the number of pieces of representative image data that can be stored in the memory in the apparatus is limited. Accordingly, in order to also display, in a list, representative images other than the representative images already stored in the memory, it is necessary to play back moving image data from the recording medium, after all. As a result, there has been the problem that it takes time to update a screen showing a list of representative images. Further, there is the problem that it further takes time if a picture (frame) in the middle of a moving image is designated as a representative image, rather than the first picture of one scene.